G. Calvin Mackenzie, a professor at Colby College, voted against Maine's Clean Elections Act ten years ago. Now he's seen it in action - and he's changed his mind. Read his column on his newfound support for the Clean Elections system in the Kennebec Journal.  Mackenzie cites the rising number of contested races and the level playing field for consesting those races among other strong points of the system, and confesses he was mistaken in his original presumption that public financing would encourage an explosion of "fringe" candidates.  As to the goal of the Act - break the hold of special interest money on legislators and public policy, Mackenzie acknowledges its success:   There can be no question that the ability of special interest groups to curry favor with legislators has been narrowed by the Clean Elections Act. In 2006, 81 percent of all legislative candidates received public funding; none of them could accept direct contributions from special interests. Lobbyists for special interests will still roam the halls of the state capitol. Nothing wrong with that. But most legislators will now be free to listen to the substance of their arguments and to respond out of interest, not obligation. This was a goal of the advocates for clean elections and it has been largely achieved.